Antidepressant and Antimanic Medications: Continuation-Phase Procedures
Once a patient has achieved a full response, the continuation phase begins and lasts for 4-6 months. Patients are usually seen every 4-6 weeks during this phase. The primary tasks of this phase are to monitor response and to assess side effects, and the primary objective is to prevent relapse. If maintenance treatment is not planned, medication should be gradually tapered over 4-6 weeks at the end of this phase.

Several factors are associated with a higher risk of relapse and need to be considered before discontinuation of medication is started. Patients with residual symptoms, patients with significant psychosocial problems, and patients with a history of prior relapse or recurrence are at increased risk for recurrence after continuation therapy. Given the high rates of recurrence of MDE and mania, most patients should be encouraged to strongly consider maintenance treatment.

Maintenance-Phase Procedures
The purpose of maintenance treatment is the prevention of recurrence. Several factors influence the decision to use maintenance treatment. Patients with two or more prior MDEs or two or more prior episodes of mania, patients with more severe episodes, and patients with a risk of suicide should be strongly encouraged to consider maintenance treatment. Patients with multiple mild episodes spaced at long intervals and with complete interinterval recovery may choose not to use maintenance treatment.

Strong data now suggest that maintenance antidepressant and antimanic treatments should be used at the full therapeutic dose during this period (Kupfer 1991). Patients should be seen every 4-12 weeks for the first year of maintenance treatment and at 6- to 12-month intervals thereafter. The frequency of visits during this phase should be individualized based on psychosocial factors, compliance, and the presence of symptoms and side effects.

Patients taking antimanic agents should have drug plasma levels determined and blood tests performed every 6 months to 1 year so that the clinician can assess possible metabolic effects. For lithium this workup includes thyroid and renal tests, and for carbamazepine and valproic acid this workup includes a complete blood count and tests of liver function.